The present invention relates to carbapenem antibacterial agents in which the carbapenem nucleus is substituted at the 2-position with a naphthosultam linked through a CH.sub.2 group. The naphthosultam is further substituted with various substituent groups including at least one cationic group --A--Q--L--B.
The carbapenems of the present invention are useful against gram positive microorganisms, especially methicillin resistant Staphylococcus aureus (MRSA), methicillin resistant Staphylococcus epidermidis (MRSE), and methicillin resistant coagulase negative Staphylococci (MRCNS) and are also effective against gram negative organisms. The antibacterial compounds of the present invention thus comprise an important contribution to therapy for treating infections caused by these difficult to control pathogens. There is an increasing need for agents effective against such pathogens (MRSA/MRCNS) which are at the same time relatively free from undesirable side effects.